1. Field of the Application
The present application relates to the stator of an axial compressor. More particularly, the present application relates to a stator of an axial turbomachine comprising main blades and auxiliary blades associated with the main blades. The present application also relates to an axial turbomachine fitted with a stator in accordance with the present application.
2. Description of Related Art
In order to straighten their annular flows, axial turbomachines have stators. These arrays of blades are located downstream of each annular row of rotor blades. They deflect an annular flow so as to convert the tangential component into an axial component. This flow is then able to be re-accelerated by a further annular array of rotor blades located downstream.
A stator generally has an inner shell and an outer shell between which the stator blades extend radially. In operation, the annular flow may break away from the blades, thus creating entropy that reduces the turbomachine's efficiency.
Patent FR2939852A1 discloses a bladed stator fitted with intermediate blades. These can be carried by an inner shell or an outer shell. Their dimensions are smaller than those of the stator blades and they are located in the downstream part of the stator, recessed relative to the main blades. This stator architecture is intended to reduce stalling at the shell. However, stalling can still occur on the suction side of the blades. They cause vortices which further reduce the turbomachine's efficiency.
Patent EP1927723B1 discloses a stator stage of a turbomachine axial compressor. A series of slats are located on the suction side of each blade. The slats reduce secondary flows between the blades. However, they are located axially at the blades. Stalling may however be observed on the suction surface of the blade, close to its trailing edge. This stalling generates entropy that reduces the turbomachine's efficiency. The presence of a plurality of slats reduces the flow area in the annular stream, which creates pressure drops.
Although great strides have been made in the area of stators for axial compressors, many shortcomings remain.